1. Field of the Invention
The present invention relates to a sealing device according to a seal technology. The sealing device according to the present invention is used, for example, in an automobile related field or a general purpose machine field.
2. Description of the Conventional Art
Conventionally, as shown in FIG. 7, for the purpose of increasing a pump amount of a seal lip 51, there has been known a sealing device provided in an atmospheric side inclined surface 52 of the seal lip 51 with a screw 53 which exerts a pumping action in relation to a sealing fluid.
However, in the sealing device with the screw 53 as mentioned above, in the case that an external dust in an atmospheric side Y intrudes in the screw 53, the intruding dust turns according to a rotation of a rotating shaft 55 so as to move in a circumferential direction, the moving dust comes into contact with the screw 53, and the contact dust moves toward a lip end 54 along the screw 53. As a result, the dust is trapped between the lip end 54 and the shaft 55, a gap is generated between the lip end 54 and the shaft 55, and there is fear of a problem that the sealing fluid (an oil or the like) leaks from the gap.